Please Note

MarineEngine.com does not offer troubleshooting assistance or repair advice by email or by telephone. You are invited to join our public Boat Repair Forum to seek assistance from other members. You may also visit the Boat Motor Manuals section of our site to obtain a service manual.

Different wot rpm numbers

Hi all, I wanted to figure out my WOT rpm since I know the prop I'm running seems like it could be over revving motor. I picked up a tachometer that wraps around spark plug wire. So on bottom cylinder I was reading 480-510 rpm at idle and 2890-2910 rpm at WOT. I swapped plug wires and on top cylinder I got 690-720 rpm idle and 5920-5930 rpm WOT. Any idea why the difference between cylinders, coil going bad? My manual says 4500 rpm for EOT which I thought sounded low for a 2 stroke? I have a 82 Johnson 35hp J35ELCND. I'm looking for more hole shot and stern lift so I'm trying to figure out my starting point as to how the motor is running now before I jump into changing anything. Any input would be appreciated thanks.

Re: Different wot rpm numbers

those inductive tachs settings are a problem, for lawn movers to v8's, play with settings, hope your testing on the water, high rpms on a hose is dangerous. 5000 to 5500 is common for most if 5920 turns out to be correct your getting a good hole shot.